1. Field of the Invention
The present invention relates to a method of forming a color filter to be mounted on a transparent substrate with electrodes of a liquid crystal display apparatus, and more particularly, to the processing of energizing terminal portions in case of using an electrodeposition process.
2. Description of Prior Art
In the case where a color filter is formed on a dot matrix type liquid crystal display apparatus by an electrodeposition process, generally, the color filter is formed, as shown in FIG. 3, by extending crystal driving terminals of electrodes on the signal side, providing terminals 21A, 21B and 21C for conduction during electrodeposition doubled in level by the number of colors to be colored, placing only required electrodes into conduction by conductive material 22A such as conductive tapes, silver paste, etc. from those extended farthest from a display area, immersing transparent electrodes into an electro-deposition bath liquid so that the transparent electrodes face to opposed electrodes in the liquid, and applying a current between the selected transparent electrode and opposed electrode to form a color filter on only the required electrode. When the color filter has been calcinated, the filter will be an insulating article.
Therefore, in the case where the second color electrode is placed in conductive state by a conductive material 22B for electrodeposition and a current is applied between the transparent electrode and the opposed electrode, non-conduction is formed between the first color electrode and the opposed electrode, and only the second color electrode is subjected to electrodeposition. Similarly, when the third color electrode is placed in conductive state by a conductive material for electrodeposition 22c and a current is applied between the transparent electrode and the opposed electrode, the third color electrode is subjected to electrodeposition.
In this manner, a color filter having the required number of colors is formed.
In this case, it is necessary to cover a portion of a liquid crystal driving terminal by a protective material 23 which can be removed later so that a color filter is not formed.
However, in the case of the energizing means as described above, the electrodes doubled in level required for the electrodeposition process are unnecessary portion as LCD panels. Therefore, an area of an LCD panel that can be manufactured by using a glass substrate of the same dimension is small as compared with other color filter forming processes.
For example, in the case where a color filter of three colors is formed, generally, a length of an electrode of 3 to 5 mm per color is required, and therefore, a width of about 9 to 15 mm in total on the glass substrate is required.
Further, when a central portion of a signal electrode is divided in order to increase the number of display lines due to the duty drive, terminals are necessary on both sides of a panel, requiring the width twice of the case where the central portion is not divided.
Furthermore, in the case where the signal electrode is divided and in the case where a plurality of patterns are arranged on one and the same glass substrate in a direction in which terminals are adjacent to each other, the width required by the terminal for electrodeposition further increases.